Heatwaves leading to increased concentrations of ground-level ozone, aggravating health risks: Study, Pg16

Key Highlights:

• A new study by Indian researchers links heatwaves to increased concentrations of ground-level ozone, significantly aggravating mortality risks.
• In 2024, over 830 deaths in India were attributed to higher ozone concentrations caused by extreme heat.
• The study, published in Clean Air (part of Nature journals), is the first to assess health impacts of heatwave-induced surface ozone in India.
• Researchers from IIT Kharagpur and Kerala University of Fisheries and Ocean Studies authored the study.

Detailed Insights:

• Ground-level ozone is an air pollutant formed by chemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs) in sunlight.
• Heat accelerates these chemical reactions, leading to higher ozone concentrations during heatwaves.
• While ozone in the middle atmosphere protects from UV rays, ground-level ozone is harmful to human health.
• Safe ground-level ozone concentration is around 30 parts per billion (ppb), but in many parts of India, it is already 50-55 ppb.
• Exposure to ozone affects lungs and heart, contributing to conditions like Chronic Obstructive Pulmonary Disease (COPD) and Ischemic Heart Disease (IHD).
• The State of Global Air report for 2025 indicated approximately 234,000 COPD deaths in India in 2023 were aggravated by ozone exposure.
• Increased ozone levels caused by heatwaves can persist for about three to four days after the heatwave ends.
• Agencies like the India Meteorological Department (IMD) and Central Pollution Control Bureau (CPCB) are urged to monitor ground-level ozone more extensively.

Scientific/Technical Concepts Involved:

• Ground-level Ozone: A harmful air pollutant formed near the Earth's surface from reactions of other pollutants in sunlight.
• Nitrogen Oxides (NOx): A group of highly reactive gases, often emitted from burning fossil fuels, that contribute to air pollution.
• Volatile Organic Compounds (VOCs): Organic chemicals that have high vapor pressure at room temperature, contributing to ground-level ozone formation.